What percentage of Down's syndrome patients also have congenital cardiovascular disease?

This fact is woh remembering: one-fifth of Down's syndrome patients have congenital cardiovascular disease, most commonly an ostium primum type of ASD and/or a ventricular septal defect. This is a sufficiently high incidence to justify at least one echocardiogram in each of these children's lives. Affected children are also paicularly vulnerable to seizures, and as adults may develop an Alzheimer-like dementia in their mid 40s. Ref: Wyatt C., Kemp W.L., Moos P.J., Burns D.K., Brown T.G. (2008). Chapter 6. Genetic Disorders. In C. Wyatt, W.L. Kemp, P.J. Moos, D.K. Burns, T.G. Brown (Eds), Pathology: The Big Picture.